a hell of

a hell of a or one hell of a  {adj.} or  {adv. phr.},  {informal}
Extraordinary; very.
He made a hell of a shot during the basketball game.
Max said seven months was a hell of a time to have to wait for a simple visa.
The fall Max took left one hell of a bruise on his knee.
Categories: {adj. phr.} {adv. phr.} {informal}